Apparatus for producing air-gas



Sept. 19, 1933. R, W. THOMAS APPARATUS FOR PRODUCING AIR-GAS Filed July 3, 1930 4 Sheets-Sheet :J1/muto@ W fms .QMMNH R. w. THOMAS 1,927,379

APPARATUS FOR PRODUCING AIR-GAS Filed July 3, 1930 4 Sheets-Sheet 3 Sept. 19, 1933.

`Patented Sept. 19, 1933 UNITED STATES 1,927,379 APPARATUS Foa PRoDUclNG Ala-GAS Rosswell Thomas, Detroit, Mich., assigner to Phillips Petroleum Company, Bartlesville,

Okla., a corporation of Delaware Application July 3, 1930. Serial No. 465,757

6 Claims. (Cl. 261-26) This invention relates to improvements in apparatus for producing air-gas from inammable liquids.' 1

One of the salient objects of the invention is to eliminateicondensation troubles in connection with such systems, and provide improved mechanism. Thesystems heretofore known are incapable of producing a constant caloric value mixture with the dew point so low that'condensation will not result, under abnormal temperature conditions. A t the present time, the caloric value usually ranges from about 1200 to 1600 B. t. u. per cubic foot, depending upon the pressure in the. system, the temperature of the liquid 15. in the tank, and on the degree of equilibrium obtained between the air and the liquid fuel. Where pentane is used as such a fuel, there is, of course, a small caloric value fluctuation which is caused by the batch distillation of the pentane, which is, as is' known, a mixture of a small amount of butanefa considerable percentage of iso-pentane, a large amount of normal pentane, and a very little hexane and heavier.

My improved system has been designed to eliminate the objections found in the known systems, and I believe they will greatly increase the salability of such air-gas machines, and the liquid ',fuel supplied for such machines. will alsovresult in a greater amount of customers satisfaction, and areduction in service calls, due to improper installation or improper operation.

They' will also entirely eliminate the adverse effect of unusual temperature conditions with respect to perfect functioning of the system.

Above au, they will give a uniform gas whieh'wiu not require frequent adjustments of the burners, and which will allow a higher thermal efficiency to be maintained on the connected appliances.

A further object of the invention is to provide an apparatus which will include a maximum number of known parts of the old systems, so that a known system may be converted into my system with a minimum of expense.

With the foregoing objects outlined and with other objects in view which will appear as the description proceeds, the invention consists in the novel features hereinafter described in detail, illustrated in the accompanying drawings, and more particularly pointed out in the appended claims.

' Referring to the drawings, e

Fig. 1 is a side elevation ofl one form of my improved apparatus.

f5 Fig. 2 is a vertical sectional view of an elec-v They Aa pipe 25 .which joins the air pipe .17 at the T trically operated pump forming part of the apparatus shown in Fig. 1.

Fig. 3 is a'modication of the liquid fuel tank and vaporizing chamber of the system.

Fig. 4 is a side elevation of another form of 60 the apparatus.

Fig. 5 is a vertical sectional view of the air operated pump of this apparatus.

Fig. 6 is a side elevation of a further form of the apparatus.

Fig. 7 is a vertical sectional View of the liquid pump of this apparatus.

Fig. 8 is an 'elevation partly in Vertical section of a modied fuel storage chamber and fuel pump.

Fig. 9 is a similar view of another embodiment 70 of like parts. A

Fig. 10 is a vertical sectional viewof another form of fuel pump.

In the embodiment of the invention illustrated in Figs. 1f and 2, an air pump 11 which is driven 75.- by an electric motor 12, draws air through a pipe 13, from adiaphragm or rotary air meter 14 to which the air is fed by a pipe 15 having a screened air intake 16.

The metered air is forced by the pump through so a discharge line 17, into a vaporizing chamber 18 which is of the flash type.

The movement of the meter 14 operates gears (not shown) in a gear box 19, and when these gears move to a predetermined degree, they actuate an arm 20.which closes an electric switch 21 that is interposed in a circuit which has wires 22 extending to an electrically operated pump 23 that is arranged within a liquid fuel tank 24.

From the foregoing it will be understood that each time a predetermined volume of air passes through the meter 14, the switch 21 will be closed to cause the pump 23 to force a measured charge of 'liquid fuel from the pump 23 upwardly through 95 26 in which the liquid is initially mixed with the air, and from which th'e'fuel travels on withthe air into the vaporizing chamber 18. In this chamber, the fuel is completely vaporized, and mixes with the air, and as both the air and the fuel are introduced in measured quantities, it will be understood that the desiredair-gas mixture will be formed in thev vaporizing chamber.

tion, and when the pressure in the chamber 18 reaches a predetermined minimum, the switch 28 will be closed, whereby current from service wires 29 may flow from the switch through wires 30 of the electric motor 12, so that adecrease in pressure in the chamber 18 will act to start the motor 12, and this will result of course, in the operation of the air pump 11, and the feeding of additional air and liquid fuel into the vaporizing chamber.

From the foregoing it will be understood that I propose a flash vaporization procedure, in which the metering liquid pump 23 runs in synchronism with a positive meter 14 through which the air supplied to the system is passing, and in my procedure, I can employ the usual compressor 11 and pressure switch 28 without any change in construction or in operating pressure range. However, I depart from the usual system by placing the air meter 14 on the suction side of the compressor 11, instead of on the pressure side thereof, so that the meter 14 always operates with atmospheric pressure on its intake, and a very slight negative pressure on its outlet. 'Ihe differential pressure through the mter is of course low, and does not appreciably affect the capacity of the compressor, which is preferably of the rotary type. Instead of having the usual tally or index attached to the meter 14, I use a train of gears in the box 19 to operate the electric switch 21, whereby, when a certain predetermined amount of air has been passed through the meter, an electric impulse is transmitted through the connecting line 22 to the electrically actuated pump 23, which is located in the bottom of the fuel storage tank. This pump has a given displacement, or in other words, it has a definite bore and stroke, and being submerged under the liquid level, its cylinder 23a always completely lls on the suction stroke. Therefore, it delivers exactly measured and predetermined amounts of pentane or other suitable liquid fuel through its discharge line 25, on the discharge stroke. In other words, for any given amount of air passing through the compressor suction meter 14, a certain predetermined volume of liquid fuel is handled by the pump.

It will be noted that this pump is suspended from the depending pipe 25, which preferably extends up through a sleeve 24a, which projects from the underground fuel tank to the ground level. A removable cover plate 24h closes the the top of this sleeve, and carries a smaller sleeve 24e through which the pipe 25 passes. With a construction of this sort, when the cover plate 24h is loosened, the pipe 25 and the pump 23 can be lifted out of the tank as a unit, to facilitate cleaning, repairing or replacement. It is of course understood that in domestic installations, the fuel tank will be buried below the surface of the ground, and preferably below the frost line, and by means of the suggested attachment, the pump can readily be inserted or withdrawn. Its suction, will, of course, come directly from the fuel .in the tank, and the pump is to be submerged at all times in the liquid, and to this end, the

fuel tank can be provided with a sump at its bottom, (see Fig. 8), into which the pump extends. The pump illustrated,- is operated on the solenoid principle, that is, it is a single cylinder, single acting pump with the valved plunger 23h forced to one end of its stroke by means of a coiled spring 23e. It is moved to the opposite end of its stroke by a solenoid winding 23d 'tion from the incoming air might be frozen in which coacts with the magnetic cord or plunger 23h.

When the circuit in which the solenoid is interposed is energized by a predetermined movement of the air meter, the pump 23 discharges a small quantity of liquid fuel into the Vaporizing chamber 18, and the pump plunger is immediately returned to the other end of the stroke by the spring 23e, the moment that the circuit is broken by the switch 2l.

It is manifest that the transmittal of the power or the correlation of the meter control mechanism and the pump. 10 can be accomplished by mechanical, rather than electrical means.

The tank which I propose to use on a domestic outfit, or on small industrial installations, is of the horizontal cylindrical type, divided into two unequal compartments by an imperforate bulkhead or partition 24d. The larger section of the tank is used for liquid storage, and has three connections to the'exterior or to the surface of the ground; one, a filling connection 24e, through which tolpour the liquid fuel; two, a gauging device 24j which may be actuated by a float to indicate the liquid level in the tank, and three, the tubular neck or riser 24a through which the pump assembly is inserted, and from which it can be readily removed. The three connections may all be independent as illustrated, or might be combined, and one of them may act as a vent connection from the top of tank 24 to the atmosphere, if desired.

rhe smaller portion 18 of the tank contains no liquid but acts as the vaporizer. It may be only about two feet in length, and say thirty or thirty six inches in diameter. A thirty inch diameter circle has an area of almost five square feet; therefore, a two foot long cylindrical portion will give about ten cubic feet of volume,115 which will perhaps be the minimum size that will work emciently on a small outt. The liquid discharged from the remote control pump 23 passes into this vaporizing chamber with the air. The finished gas, saturated with the hydrocarbon fuel vapors, passes olf from the chamber 18 to the points of use.

The latent heat of vaporization will be supplied from two sources, (a) by the sensible heat of the air pumped into the vaporizing chamber from the compressor, and (b), by the heatl abstracted from the surrounding earth, and from the liquid fuel in the other section of the-tank through the bulkhead.

A simple calculation indicates that unless an extremely low B. t. u. gas is being made, the sensible heat of the air constituent of the gas will not be sufficient to supply all of the latent heat of vaporization. This is not of serious concern, as the latent heat will flow in from the surrounding tank, and the adjacent objects, as v it does at the present time in the typical gasoline gas machines.

It is sometimes advisable to provide some baffles 18a in the vaporizing section of the tank, to prevent the air pumped in by the compressor from short-circuiting and passing out to the points of use, without becoming properly saturated with the fuel. As the latent heat of vaporization taken on by the vaporizing fuel in this compartment may chill the compartment and the incoming air to such an extent that the air will be partially dehydrated, and in certain cases, the condensa- 15a the vaporizing chamber, the vaporizing chamber of the tank is provided with a drain or water eduction pipe 18b to remove the condensate from time to time.

It is, of course, obvious that the chamber 18 will also serve as a gas storage space. In the usual outfit, the compressor starts when the pressure reduces to three pounds per square inch, and stops when it is raised to about six pounds per square inch, due to the actuation of the switch 28. This pressure range affords a storage of such magnitude as compared with the ordinary domestic rate of use, that the compressor runs spasmodically and infrequently. The heat of compression, of course, helps out on the supplying of the latent heat of vaporization to the boiling fuel.

By adjusting the gear mechanism in the box 19, the desired ratio between the air pumped into the system and the fuel pumped into the system can be maintained, thereby giving a finished gas of any kdesired calorific value, within the limits of the temperatures and pressure employed. It will undoubtedly be advisable in most cases, to adjust the caloriiic value of the finished mixture to the neighborhood of 530 B. t. u. per cubic foot.

This will allow the use of standard appliances made by a large number of stove 'manufacturers which have already been adapted for highly efficient use with butane-air carburetted gas. 'Ihe flame characteristics, and iniiammability limits of pentane-air mixtures are almost identical with those of the butane-air mixture. Consequently, it is advisable to select a calorific value such as mentioned above.

Obviously, the pressure range on the system need not necessarily be three to six pounds, but may be anything within reason, but the maximum pressure is limited by the construction of the vaporizing and mixing chamber 18.

When a pressure system is used, it will be necessary to have a conventional reducing regulator on the finished gas line, anterior to the point where the gas enters the appliances or the house piping.

No pressure other thanthe vapor pressure of the liquid fuel is carried onthe liquid storage portion 24 of the outfit. If pentane is used as the fuel, at ordinary ground temperatures, this vapor pressure will be at, or less than atmospheric pressure. Therefore, it will be a simple matter to replenish the fuel supply, even while the apparatus is running. This is not the case with the majority of gasoline-gas machines at the present time, as most of them carry a pressure on the liquid container, which must be released by shutting down the machine before additional fuel can be poured into the underground tank. In the ease of large `restaurants and semi-industrial users, this periodic interruption'of gas service is a serious handicap. K

The installation which I have invented will be only slightly more expensive to manufacture than the conventional equipment, as it uses practically allv of the present conventional gas machine parts, aid in addition, has the positive meter 14 on the suction side of the compressor, the electrical contacting device or switch 21, the tank extension or additional vaporizing compartment 18, and the electrically or otherwise actuated fuel pump 23, but I believe that the advantages enumerated will more than overcome the price differential, particularly as gas machines are sold in most cases to consumers who can afford a fairly high initial cost, and who look for operating economy, rather than low first price.

Instead of embodying the fuel storage chamber and the vaporizing chamber in a single tank, these parts may be separated from one another, as shown in Fig. 3. For example, the fuel can be stored in a horizontal tank 24h, having a filling connection 24i, a gauge connection 24k, and a neck 24m; the latter permitting the insertion or removal of the fuel pump 241i.

In this modification, the fuel is forced by the pump upwardly through the conduit 24o, into the air pipe 24p, which discharges into a separate vaporizing tank 18h, from which the finished air gas is discharged by way of pipe 181'.

vIn the modification illustrated in Fig. 4, most of the parts are the same as in Fig. 1, but in this case, a part of the air which is forced by the compressor through the pipe 17a, instead of flowing directly to the vaporizing chamber, is diverted into a branch pipe 17h which leads to the casing of a three-way valve 17e, the active member of which may be actuated by a solenoid 17j. This solenoid takes the place of the pump solenoid 23d of Fig. 1, and it `is interposed in the circuit 17g, in Which-the control switch 21a is arranged.

When the valve 17e is opened, air from the branch 17h can flow through a pipe 17h which extends downwardly into the fuel tank and carries at its lower end, an air actuated pump 23h. The latter includes a cylinder in which a difierential piston 23i is arranged, such piston being forced downwardly by air pressure, and upwardly by a coil spring 23k. When the piston rises, 10 it draws liquid fuel into the cylinder through the suction valve 23m, and when the piston descends, this fuel is forced through the discharge valve 23u, into a pipe 23o, which rides in parallel-relation to the pipe 17h, and joins the pipe 17a at 11 the point 23p.

' In this construction, when the air meter 14a has moved a predetermined degree, the switch 21a will be closed, so that the solenoid 17j will be energized to open the Valve 17e and to close the exhaust l'li of that valve. Consequently, some of the pressure air will be diverted and passed through pipes 17h and 17h, into the upper end of the cylinder of the fuel pump. As a result, piston 23i will be forced downwardly, and a measured charge of liquid fuel from the pump will be forced through the pipe 23o, into the pipe 17a, so that it will travel with the main stream of air to the vaporizing chamber. When the switch 21a opens, a spring or the like will return the valve 17e to a position to close the branch 17h, and then the spring 23k will lift the piston, and any air trapped in the upper portion of the pump cylinder and in the pipe 17h, will escape to atmosphere through the outlet 172'.

This scheme eliminates the electrically actuated pump, and substitutes one driven by the air pressure from the compressor through a control valve 17e, actuated by any suitable means from 140 the air meter 14a. It will be noted that the pump is of the dierential piston type, with venting holes 231" in the cylinder at the step of the piston. This permits the compressor to discharge air pressure to force the liquid into the vaporizer at the same pressure. This scheme allows the compressor to run continuously, and injects fuel at the proper time in accordance with the motion of the suction meter to maintain the desired caloric value.

The system shown in Fig. 6 is similar to that shown in Figs. 1 and 4, with the following exceptions. The air discharge line 17m of the compressor, instead of passing directly to the vaporizing chamber, is extended as shown at 171i, into the fuel storage compartment, and is connected at its lower end to the head of a pump cylinder 23s, in which a piston 2315 reciprocates. When this piston rises un'der the influence of a spring 23u, liquid is drawn into the cylinder through the suction valve 231), and then, when the piston descends, this measured charge of liquid is forced through the discharge valve 23u), into a pipe 23a: which leads from the pump into the vaporizing chamber.

When the piston descends to its lowest point, it uncovers a by-passageway 231;` which leads from the cylinder to the pipe 23x, and consequently, the air above the cylinder is discharged into the pipe 23x, so that it travels with the fuel into the' vaporizing chamber.

In this form of the invention, the motor 12a which drives the compressor is not only controlled by the pressure operated switch 28a, but also by a switch 2lb which is actuated by the air mey ter 14h. Of course, the switch 2lb is interposed in the control circuit 50 of the air pump motor.

In accordance with my invention, where it is desirable to use an electrically operated pump for the fuel, the electric elements need not be submerged in the fuel tank. For example, as shown in Fig. 8, the tank 60 may be provided with an upwardly extending sleeve 61 to support a solenoid 62 arranged above the tank. From this solenoid, a pipe 63 extends into the tank, and this pipe is connected at its lower end to the cylinder 64 of the pump. In this case, a rod 65 which extends through the pipe, joins the pump piston 66 to the solenoid core 67, so that the piston may be elevated by means of the solenoid, and may be depressed by the spring 68. The discharge line 69 of the pump may extend along the pipe 63 from the outlet of the cylinder to the exterior of the tank, and from the exterior of the tank, it is of course, led to the vaporizing chamber.

In this modification, the intake valve 70 of the pump is arranged in the bottom of the cylinder, and the outlet valve 71 is in the lower portion of the piston.

As heretofore mentioned, any one of the fuel pumps can be located in a sump at the bottom of the storage tank, and in Fig. 8, such a sump is shown at 72, and the pump is submerged therein.

In place of the solenoid actuated pump, I may employ a motor operated pump, as shown in Fig. 9. In this case, an electric motor 75, arranged above the tank, has its shaft 76 extending downwardly into the tank, through a casing 77 which supports at its lower end, any suitable type of pump 78, for instance, a rotary gear pump.

The motor shaft drives the pump and the liquid fuel is drawn from the sump 79 of the tank, into the intake pipe 80 of the pump. From the pump, this fuel is discharged by way of the pipe 81 which leads to the vaporizing chamber.

Of course, the solenoid shown in Fig. 8, and theelectric motor 75 shown in Fig. 9, will be controlled in the same manner as the solenoid of the fuel pump in Fig. 1.

The pump shown in Fig. v5 may be modified,l as illustrated in Fig. 10. In this case, the piston of the pump may be connected by a rod 91 "to an imperforate diaphragm 92, which divides the pump cylinder 93 into upper and lower compartments, and prevents air in the upper compartment from passing into the lower compartment, or liquid from the lower compartment passing into the upper compartment.

A spring 94 functions to return the diaphragm to its upper position, and a suitable stop 95 limits the upward movement of the diaphragm.

In this example, the fuel is drawn into the pump Vthrough the intake valve 96, and is discharged by way of the outlet valve 97, into the fuel discharge line 98, which will lead the fuel to the vaporizing chamber.

It is manifest that this system may be modified or changed to supply gas for pipe line distribution in small towns. This would be particularly advantageous in tropical or semi-tropical climates where the fact that the dew point of pentane-air mixtures is slightly higher than the corresponding dew point of butane-air mixtures, would not be a disadvantage. The fact that this new system will allow the shipment of pentane in steel drums, and that these shipments are accepted on most any railroad orV freight vessel, makes the system advantageous over liquefied gas installations.

In the case of town gas plants, a large pentane storage tank can be located above the ground, preferably having a capacity sufficient to hold more than a tank car of fuel. This pentane can be pumped from the tank car to the storage tank, and on the bottom outlet of the latter, a proportioning liquid pump can be flanged with a gate valve between the pump and the tank. This will give the pump the benefit of the full head of liquid in the tank, but by closing the gate valve, the pump can be removed and replaced, or

Y repaired at will.

For a low pressure holder and lower pressure gas distribution system, the air meter in such a plant can be installed either on the suction or the discharge side of the blower or air compressor, because on one side the pressure would be atmospheric, and on the other, it would be the back pressure created by the holder, which is constant at all times on a single lift water-sealed type holder. In this case, the airr meter can be so located as to be adjacent to the fuel pump, so that the meter gears and mechanism may be connected directly to the pump by linkage or mechanical means instead of the long distance electrical control mentioned for the individual household plant. It is obvious, however, that y electric transmission can also be used in the larger gas plants, and that the same degree of precision of proportioning the air stream and the liquid carburent injection can be maintained, regardless of exact methods involved.

In case of the town gas plant particularly, but also if desirable, on the household plants, a back pressure or spring loaded valve should be placed in the discharge line from the pump, as shown at 100 in Fig. 1, to avoid vaporization within the pump cylinder itself. This light excess back pressure can easily be overcome by the pump without the consumption of any appreciably greater amount of energy, and may make for accuracy of metering or proportioning of the liquid.

So far as I am aware, the idea of putting a meter on the suction side of the compressor or blower, in order to havethe meter operating at a constant pressure, is entirely new, and I believe it is also novel in systems of this character, to place the liquid proportioning pump in the bottom of the fuel tank.

The same ideas of liquid proportioning can undoubtedly be-applied to fuels other than pentane, and I desire to be understood that I intend to employ the system with any or all of the hydrocarbons and their mixtures, which may be retained in storage as a liquid, either under their own super-atmospheric vapor pressures, or at vapor pressures equal to or less than atmospheric.

While I show the vaporizing chamber as the finished gas storage tank, it is of course feasible to use a variable volume constant pressure holder for the storage of the finished gas, which will eliminate the necessity for a house regulator or governor. It probably would not be feasible to pump the air and inject the liquid fuel into the interior of such a holder, particularly if the same was water-sealed, because of the low temperature that will be developed by the latent heat of vaporization of the fuel.- If a lift type holder is used for storage of the finished gas, it could be used in Vconnection with a separate Vaporizing chamber of comparatively small volume, from which the finished gas will pass through `the lift type holder, which could be located in the basement of the house, or at any convenient place.

Referring again to Fig. 1 of the drawings, it will be noted that if a constant pressure variable volume air-gas storage chamber is used in place.

of the chamber 18, the rise and fall of the movable element of said chamber may be taken advantage of for actuating the starting and stopping of the air pump 11, and coincidentally of controlling the operation of the fuel injection pump 25. The constant pressure variable volume air-gas storage chamber may be a liquid sealed gasometer.

While I have disclosed what I now consider tol be preferred embodiments of the invention in such mannerthat thefsame may be readily understood by those skilled in the art, I am aware that changes may be made in the details disclosed, without departinga from the spirit of the invention, as expressed in the claims.-

What I claim and desire to secure by Letters Patent is:

1. An air-gas machine comprising a Vaporizing chamber, a conduit for feeding air to said chamber, an air compressor interposed in said conduit, a motor for driving said air compressor, means responsive to pressure conditions in the vaporizing chamber for controlling the operation of the motor, an air meter interposed in said conduit anterior to the compressor, a liquid fuel storage chamber, a pump in said storage chamber for forcing liquid fuel from the storage chamber to the vaporizing chamber, and means responsive to movements of the air meter for controlling the operation of said pump. v

2. An apparatus of the character described, including an air-gas storage chamber, means for feeding air and liquid fuel into said chamber, an

Iair conduit leading to said means, an air pump interposed in said conduit, a motor for driving said pump, means responsive to pressure conditions in said chamber for controlling the motor, a movable air meter interposed in said conduit anterior to said pump, a liquid fuel storage chamber, a fuel pump in the fuel storage chamber, a conduit connecting the outlet of the fuel pump to said first mentioned means, and means responsive to movements of the air meter for controlling the operation of one of said pumps.

3. An air-gas machine comprising an air-gas storage chamber, means for introducing air and liquid fuel into said chamber, an air conduit having one of its ends connected to said means and its other end provided with an air intake, an air pump interposed in said conduit, a motor for driving said pump, means responsive to pressure conditions in the chamber for controlling said motor, an air meter interposed in the conduit between the pump and the air intake, a liquid fuel storage chamber, a fuel pump arranged in said chamber and having its' outlet operatively` connected to the first mentioned means, and means actuated by said meter for controlling the operation of the fuel pump.

4. An air-gas machine comprising an air-gas storage chamber, means for introducing air and liquid fuel into said chamber, an air conduit leading from atmosphere to the last mentioned means, an air pump interposed in said conduit, a motor for actuating said pump, means responsive to pressure conditions in said chamber for controlling said motor, an air meter' interposed in the conduit between the pump and the inlet end of the conduit, a liquid fuel storage chamber, aA fuel pump for forcing fuel from the liquid storage chamber to the air-gas storage chamber and having its outlet operatively connected to the rst mentioned means, and means actuated by said meter for controlling one of said pumps.

5. An air-gas machine comprising antair-gas storage chamber, means for introducing air and liquid fuel into said chamber, an air conduit leading from atmosphere to the last mentioned' means, an air pump interposed in said conduit, a motor for actuating said pump, means responsive to pressure conditions in said chamber for controlling said motor, an air -meter interposed in the conduit between the pump and the inlet end of the conduit, a liquid fuel storage'chamber, a fuel pump for forcing fuel Ifrom the liquid storage chamber to the air-gas -st'orage chamber and havin'g its outlet operatively connected to the first mentioned means, and means actuated by said meter for controlling said fuel pump.

6. An air-gas machine comprising an air-gas storage chamber, meansfor introducing air and liquid fuel into said chamber, an air conduit having one of its ends connected to said means and its other end provided with an air intake, a motor operated air pump interposed in said conduit, an air meter interposed in said conduit anterior to said pump, a liquid fuel storage chamber provided with an upwardly extending sleeve, 

